Affiliation:
1. College of Resources and Environment, Southwest University, Chongqing 400716, China
2. Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, Southwest University, Chongqing 400716, China
3. Tongliang District Agricultural Technology Extension Service Center, Chongqing 402560, China
4. Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210018, China
5. Chongqing Academy of Agriculture Sciences, Chongqing 400000, China
Abstract
Intensive vegetable production has been characterized by high nitrogen (N) fertilizer input in southwest China. Optimizing the N fertilizer rate is the basis for the optimal management of regional N fertilizer. A two-year field experiment with five N fertilizer rates was conducted during 2019–2021 in southwest China, and the aim of this study was to identify the effects of different N application rates on yield, dry matter biomass (DMB), N uptake, N use efficiency (NUE) and soil mineral N (Nmin) residues for Chinese cabbage (Brassica chinensis L.) and further determine the critical plant N concentration and root-zone soil Nmin residues required to reach the maximum DMB of Chinese cabbage. Five N treatments were established: control without N input (CK); optimal N fertilizer rate decreased by 30% (70% OPT, 175 kg N ha−1), optimized N fertilizer rate (OPT, 250 kg N ha−1), optimal N fertilizer rate increased by 30% (130% OPT, 325 kg N ha−1) and farmers’ N fertilizer practice (FP, 450 kg N ha−1). The N source in all treatments was conventional urea (N ≥ 46.2%). The results showed that the total yield of Chinese cabbage followed a “linear-plateau” trend with an increasing N fertilizer rate. There was no significant difference in yield between the OPT, 130% OPT and FP treatments. The aboveground plant DMB and N uptake showed a ‘slow-fast-slow’ pattern with the growth period. There was no significant difference in aboveground plant DMB and N uptake between the OPT, 130% OPT and FP treatments. Moreover, the OPT treatment significantly increased the aboveground plant DMB and N accumulation by 29.6% and 40.5%, respectively, compared with the 70% OPT treatment. The OPT treatment significantly increased the NUE by 23.8%, 31.2% and 43.1% compared with that in the 70% OPT, 130% OPT and FP treatments, respectively. The linear-plateau model provided the best fit for the relationship among aboveground DMB of Chinese cabbage, plant N concentration and root-zone soil Nmin content. The critical root-zone soil Nmin and plant N concentrations were 94.1, 63.4 and 68.3 kg ha−1 and 34.4, 33.5 and 32.9 g kg−1 during the rosette, heading and harvest periods, respectively. In summary, compared to the FP treatment, the optimized N fertilizer rate (250 kg N ha−1) could significantly reduce the N application rate, maintain yield, increase aboveground plant DMB and N uptake, and improve NUE. Moreover, the study has great significance for guiding the green utilization of vegetable N fertilizer in southwest China.
Funder
National Natural Science Foundation of China
Cultivated land Quality Improvement in Chongqing during 2022—Investigation and evaluation of soil quality in vegetable base
Innovation Research 2035 Pilot Plan of Southwest University
Foundation of Graduate Research and Innovation in Chongqing under Project
Subject
Agronomy and Crop Science
Reference39 articles.
1. Impact of environmental factors on product quality of greenhouse vegetables for fresh consumption;Gruda;Crit. Rev. Plant Sci.,2005
2. Global vegetable supply towards sustainable food production and a healthy diet;Dong;J. Clean. Prod.,2022
3. Innovative management programme reduces environmental impacts in Chinese vegetable production;Wang;Nat. Food,2020
4. NBSC (2022). China Statistical Yearbook, National Bureau of Statistics of China.
5. Reducing potential of chemical fertilizers and scientific fertilization countermeasure in vegetable production in China;Huang;J. Plant Nutr. Fertil.,2017